Electrical equipment enclosures such as those described within U.S. Pat. No. 4,683,517 entitled "Integrated Lighting Panelboard and Wiring Gutter Assembly" which contain electrical switches are often custom assembled at the point of manufacture to accommodate the size and number of switches contained therein.
U.S. Pat. No. 5,151,842 entitled "Switchboards and Panelboards Having Interlock and Load Selection Capabilities" describes such enclosures when used to contain electronic circuit breakers and the like.
A more recent example of an electrical equipment enclosure is found within U.S. Pat. No. 5,424,911 entitled "Compact Motor Controller Assembly". This patent describes motor starters and contactors used to efficiently start and stop industrial rated electric motors. One such motor starter is found within U.S. Pat. No. 5,341,080 entitled "Apparatus and Three Phase Induction Motor Starting and Stopping Control Method".
In such state-of-the-art motor control devices, solid state switches such as SCRs for example, are often employed to controllably switch the motor current to provide smooth motor starting and stopping function. Since the SCRs become heated upon current transfer therethrough, heat sinks in the form of large metal blocks of copper, aluminum and their alloys are required to protect the SCRs from overheating.
Other types of electrical control equipment, such as relays, contactors, control power transformers and the like are often required within the motor control compartment, the motor compartment is oversized to accommodate the heat sinks.
One purpose of the invention is to provide a modular motor control compartment that provides a separate controlled air-flow compartment for the heat sink to free-up the area within the compartment adjacent the motor control unit to facilitate space as well as to accommodate electrical connection with the motor controller unit.